code: def test_preprocessing_layer_no_combiner(self):
      network = encoding_network.EncodingNetwork(
          input_tensor_spec=tensor_spec.TensorSpec([5], tf.float32),
          preprocessing_layers=tf.keras.layers.Lambda(lambda x: x),
          preprocessing_combiner=None,
          fc_layer_params=(2,),
      )
      out, _ = network(tf.ones((3, 5)))
      self.assertAllEqual(out.shape.as_list(), [3, 2])
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from absl.testing import parameterized
  import numpy
  import tensorflow
  from tf_agents.networks import encoding_network
  from tf_agents.specs import tensor_spec
  from tf_agents.utils import test_utils
label_desc: Use image node_id 6 for calling the EncodingNetworkTest obj's underlying member method code with example usage: obj.test_preprocessing_layer_no_combiner() without return types